Naloxone depresses cocaine self-administration and delays its initiation on the following day.

摘要: While dopamine mechanisms play a crucial role in cocaine-taking behavior, the contribution of endogenous opioid systems is less clear. We assessed effects receptor blockade by naloxone (1 mg/kg, s.c.) on daily performance and subsequent initiation cocaine self-administration trained rats. Naloxone decreased rate approximately half, with effect varying from complete to no change. On day following treatment, latencies drug availability cue first were consistently longer than before treatment. Measurement brain temperature behavioral observations suggested lower normal level motivational arousal as factor for slow behavior. After infusion, however, was uniformly normal. These data suggest behavior indicate residual inhibitory consequence treatment this